In this renewal application, we will build on the successes of the past project period to further examine the biological, social, and economic conditions that shape health in the aging population of South Africa. Our program, Health and Aging in Africa: Longitudinal Studies of an INDEPTH Community (HAALSI) completed its initial 3-year grant period with the establishment of a community-based cohort with baseline data for 5,059 men and women ?40 years of age in the International Network for the Demographic Evaluation of Populations and Their Health in Developing Countries (INDEPTH) community of Agincourt, South Africa. The response rate to the baseline survey was 86%. We use the infrastructure and tools already in place for follow- up surveillance of the HAALSI cohort, and we anticipate very minimal loss to follow-up for data collection moving forward. We propose to conduct two waves of follow-up data collection at three-year intervals, allowing the longitudinal analysis of three waves of data collection and six years of follow-up for morbidity, mortality, biological, behavioral, and environmental risk factors, and physical and cognitive function. The proposed HAALSI Program includes five projects: Project 1: Alzheimer?s Disease and Related Dementias and Cognitive Impairment; Project 2: Cardiometabolic Disease in an Aging South African Cohort; Project 3: HIV and HIV Interventions to Promote Healthy Aging; Project 4: Public Policies to Improve Healthy Aging; and Project 5: Multimorbidity. The projects will be supported by four cores: Leadership and Administration (Core A), Field (Core B), Data Management and Analysis (Core C), Biomarkers and Biobanking (Core D). Each of these projects and cores will be led by investigators from both the U.S. and South Africa. All projects will share a common household and participant survey and assessment and have aims that are tightly integrated across projects to create a synergistic and dynamic program. The study design used by the HAALSI Program is finely tuned to capture characteristics specific to South Africa as well as harmonize with other HRS sister studies in India, China, Brazil, the UK, Europe, and the U.S., providing a unique opportunity to conduct cross-country comparisons of the biological, social, and economic determinants of chronic diseases and their effects on functional and health outcomes in aging populations. Such cross-country harmonized comparisons will enable scientists to identify new risk factors and understand the impact of known risk factors on a global scale. Our study will inform the current debate about whether ?standard? risk factors in highly industrialized Western countries have the same effects on health outcomes in non-Western, low income countries. Our study sets out to identify and examine the distribution of both novel and established risk factors for chronic health conditions and conduct a follow-up study to discover the predictive value of the identified biological, social, and environmental risk factors. We have built a strong set of experimental aims into this application focusing on the evaluation of public policies aimed at reducing health risks, which has direct relevance to health in the U.S.